The report shows he had what multiple experts called an “exceedingly high” concentration of fentanyl in his body when he died, according to the Associated Press who obtained the report.

Fentanyl, is the most powerful opioid in medicine and is prescribed by doctors to relieve pain from cancer. It can be made illicitly and is blamed for a spike in overdose deaths in the United States. It’s 25 to 50 times more potent than heroin and 50 to 100 times more potent than morphine, according to the U.S. Drug Enforcement Administration.

The DEA has said, “approximately two milligrams is a lethal dose for most non-opioid-dependent individuals.”

Prince, whose full name was Prince Rogers Nelson, died April 21, 2016 at age 57, after being found unresponsive in an elevator at Paisley Park, his home and recording studio in Chanhassen, Minnesota.

Since his death, information has emerged about the entertainer’s alleged abuse of prescription drugs.